The association between selected molecular biomarkers and ambulatory blood pressure patterns in African chronic kidney disease and hypertensive patients compared with normotensive controls : protocol for a longitudinal study
- Authors: Adeoye, Abiodun , Adebayo, Oladimeji , Abiola, Busayo , Iwalokun, Bamidele , Tayo, Bamidele , Charchar, Fadi , Ojo, Akinlolu , Cooper, Richard
- Date: 2020
- Type: Text , Journal article
- Relation: JMIR Research Protocols Vol. 9, no. 1 (Jan 2020), p. 8
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- Description: Background: Chronic kidney disease (CKD) is a burgeoning epidemic in sub-Saharan Africa. Abnormal blood pressure variations are prevalent in CKD and potentiate the risk of cardiovascular morbidity and mortality. Certain genetic variants (angiotensin II receptor type 1 1166 A>C and angiotensin-converting enzyme insertion and deletion polymorphisms) and biomarkers such as interleukin-6, tumor necrosis factor, soluble (s) E-selectin, homocysteine, and highly sensitive C-reactive protein have been shown to affect blood pressure variability among non-African CKD, hypertensive. and nonhypertensive CKD population. However, the contributions of the pattern, genetic, and environmental determinants of ambulatory blood pressure in African CKD have not been characterized. Understanding these interactions may help to develop interventions to prevent major cardiovascular events among people with CKD. Objective: The overarching objective of this study is to identify, document, and develop approaches to address related phenomic, genetic, and environmental determinants of ambulatory blood pressure patterns in African CKD and non-CKD hypertensive patients compared with normotensive controls. Methods: This is a longitudinal short-term follow-up study of 200 adult subjects with CKD and 200 each of age-matched hypertensives without CKD and apparently healthy controls. Demographic information, detailed clinical profile, electrocardiography, echocardiography, and 24-hr ambulatory blood pressure measurements will be obtained. Blood samples will be collected to determine albumin-creatinine ratio, fasting plasma glucose, lipid profile, electrolytes, urea and creatinine, C-reactive protein, serum homocysteine, fibroblast growth factor-23, and complete blood count, while 2 mL blood aliquot will be collected in EDTA (ethylenediaminetetraacetic acid) tubes and mixed using an electronic rolling system to prevent blood clots and subsequently used for DNA extraction and genetic analysis. Results: A total of 239 participants have been recruited so far, and it is expected that the recruitment phase will be complete in June 2020. The follow-up phase will continue with data analysis and publications of results. Conclusions: This study will help stratify Nigerian CKD patients phenotypically and genotypically in terms of their blood pressure variations with implications for targeted interventions and timing of medications to improve prognosis.
May measurement month 2017 : an analysis of blood pressure screening results worldwide
- Authors: Beaney, Thomas , Schutte, Aletta , Tomaszewski, Maciej , Ariti, Cono , Burrell, Louise , Castillo, Rafael , Charchar, Fadi , Damasceno, Albertino , Kruger, Ruan , Lackland, Daniel , Nilsson, Peter , Prabhakaran, Dorairaj , Ramirez, Agustin , Schlaich, Markus , Wang, Jiguang , Weber, Michael , Poulter, Neil
- Date: 2018
- Type: Text , Journal article
- Relation: The Lancet Global Health Vol. 6, no. 7 (2018), p. e736-e743
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- Description: Background: Increased blood pressure is the biggest contributor to the global burden of disease and mortality. Data suggest that less than half of the population with hypertension is aware of it. May Measurement Month was initiated to raise awareness of the importance of blood pressure and as a pragmatic interim solution to the shortfall in screening programmes. Methods: This cross-sectional survey included volunteer adults (≥18 years) who ideally had not had their blood pressures measured in the past year. Each participant had their blood pressure measured three times and received a a questionnaire about demographic, lifestyle, and environmental factors. The primary objective was to raise awareness of blood pressure, measured by number of countries involved, number of people screened, and number of people who have untreated or inadequately treated hypertension (defined as systolic blood pressure ≥140 mm Hg or diastolic blood pressure ≥90 mm Hg, or both, or on the basis of receiving antihypertensive medication). Multiple imputation was used to estimate the mean of the second and third blood pressure readings if these were not recorded. Measures of association were analysed using linear mixed models. Findings: Data were collected from 1 201 570 individuals in 80 countries. After imputation, of the 1 128 635 individuals for whom a mean of the second and third readings was available, 393 924 (34·9%) individuals had hypertension. 153 905 (17·3%) of 888 616 individuals who were not receiving antihypertensive treatment were hypertensive, and 105 456 (46·3%) of the 227 721 individuals receiving treatment did not have controlled blood pressure. Significant differences in adjusted blood pressures and hypertension prevalence were apparent between regions. Adjusted blood pressure was higher in association with antihypertensive medication, diabetes, cerebrovascular disease, smoking, and alcohol consumption. Blood pressure was higher when measured on the right arm than on the left arm, and blood pressure was highest on Saturdays. Interpretation: Inexpensive global screening of blood pressure is achievable using volunteers and convenience sampling. Pending the set-up of systematic surveillance systems worldwide, MMM will be repeated annually to raise awareness of blood pressure. Funding: International Society of Hypertension, Centers for Disease Control and Prevention, Servier Pharmaceutical Co.
May measurement month 2019 the global blood pressure screening campaign of the International Society of Hypertension
- Authors: Beaney, Thomas , Schutte, Aletta , Stergiou, George , Borghi, Claudio , Burger, Dylan , Charchar, Fadi , Cro, Suzie , Diaz, Alejandro , Damasceno, Albertino , Espeche, Walter , Jose, Arun , Khan, Nadia , Kokubo, Yoshihiro , Maheshwari, Anuj , Marin, Marcos , More, Arun , Neupane, Dinesh , Nilsson, Peter , Patil, Mansi , Prabhakaran, Dorairaj , Ramirez, Agustin , Rodriguez, Pablo , Schlaich, Markus , Steckelings, Ulrike , Tomaszewski, Maciej , Unger, Thomas , Wainford, Richard , Wang, Jiguang , Williams, Bryan , Poulter, Neil , M. M. M. Investigators
- Date: 2020
- Type: Text , Journal article
- Relation: Hypertension Vol. 76, no. 2 (Aug 2020), p. 333-341
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- Description: Elevated blood pressure remains the single biggest risk factor contributing to the global burden of disease and mortality. May Measurement Month is an annual global screening campaign aiming to improve awareness of blood pressure at the individual and population level. Adults (>= 18 years) recruited through opportunistic sampling were screened at sites in 92 countries during May 2019. Ideally, 3 blood pressure readings were measured for each participant, and data on lifestyle factors and comorbidities were collected. Hypertension was defined as a systolic blood pressure >= 140 mm Hg, or a diastolic blood pressure >= 90 mm Hg (mean of the second and third readings) or taking antihypertensive medication. When necessary, multiple imputation was used to estimate participants' mean blood pressure. Mixed-effects models were used to evaluate associations between blood pressure and participant characteristics. Of 1 508 130 screenees 482 273 (32.0%) had never had a blood pressure measurement before and 513 337 (34.0%) had hypertension, of whom 58.7% were aware, and 54.7% were on antihypertensive medication. Of those on medication, 57.8% were controlled to <140/90 mm Hg, and 28.9% to <130/80 mm Hg. Of all those with hypertension, 31.7% were controlled to <140/90 mm Hg, and 350 825 (23.3%) participants had untreated or inadequately treated hypertension. Of those taking antihypertensive medication, half were taking only a single drug, and 25% reported using aspirin inappropriately. This survey is the largest ever synchronized and standardized contemporary compilation of global blood pressure data. This campaign is needed as a temporary substitute for systematic blood pressure screening in many countries worldwide.
MicroRNA-34a and tert act as epi-drivers of cardiac telomere length and polygenic cardiac hypertrophy
- Authors: Booth, Scott , Marques, Francine , Prestes, Priscilla , Curl, Claire , Delbridge, Lea , Lewandowski, Paul , Harrap, Stephen , Charchar, Fadi
- Date: 2015
- Type: Text , Journal article
- Relation: Heart, Lung and Circulation Vol. 24, no. S3 (2015), p. S180-S181
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- Description: Cardiac hypertrophy is one of the main risk factors forheart failure. Here we aimed to investigate whether cardiactelomere length contributes to polygenic cardiac hypertro-phy independent of blood pressure. We also investigatedwhether changes in telomere length were due to the telomereregulators microRNA-34a,Ppp1r10(also known asPnuts)and telomerase. We used the hypertrophic heart rat (HHR),a normotensive model of polygenetic cardiac hypertrophy,and compared it to age-matched controls. Telomere length, microRNA levels, gene expression and telomerase activitywere measured in isolated cardiomyocytes and left ventricletissue using real-time PCR. Telomere length was significantlylonger in 2-day and 38-week-old HHR, but shorter at 4-and 13-week HHR. In the HHR, telomere length becameshorter early in development, while in the control straintelomere shortening was only observed in late adulthood.Telomere length was the main determinant of cardiac mass.
Dysregulation of c-kit expression parallels the development of spontaneous genetic cardiac hypertrophy
- Authors: Marques, Francine , Prestes, Priscilla , Lewandowski, Paul , Harrap, Stephen , Charchar, Fadi
- Date: 2015
- Type: Text , Conference paper
- Relation: Cardiac Society of Australia and New Zealand Annual Scientific Meeting and the International Society for Heart Research Australasian Section Annual Scientific Meeting; Melbourne, Victoria, Australia; 13th-16th August 2016; published in Heart, Lung and Circulation. Vol. 24, p. S401-S401
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- Description: Objective: The molecular processes associated with cardiac hypertrophy independent of blood pressure are still largely unknown. The hypertrophic heart rate (HHR) is normotensive and born with a reduced complement of cardiomyocytes that predisposes to cardiac hypertrophy and failure in later life. We investigated the expression of c-kit gene, a marker of cardiac stem cells and myocardial regeneration that could contribute to hypertrophy. Methods: Left ventricular c-kit mRNA expression was measured by real-time PCR in HHR and control strain in neonatal and 38-week old rats (n=7-12/group). We tested for linkage of c-kit expression with neonatal cardiac size in 197 second generation crosses (F2) of HHR and control strain. Results: c-kit mRNA was slightly up-regulated in neonatal (fold change +1.3, P=0.02) and markedly so in 38-week old HHR (+35.5, P=0.0003). Cardiac weight index was positively correlated with neonatal myocardial c-kit mRNA in the F2 population (r=0.19, P=0.007). Conclusions: In HHR hearts c-kit expression appears increased throughout life, but more so in the adult where cardiac hypertrophy is established and leading to failure. In aged hypertrophic hearts, over-expression of c-kit is likely a compensatory mechanism of the failing heart. Previous studies showed an activation of cardiac stem cells in the hypertrophic myocardium. Our study suggests that c-kit might be involved from an early age in mechanisms that lead to cardiac hypertrophy in adulthood.
Coronary artery disease : Why we should consider the Y chromosome
- Authors: Molina, Elsa , Clarence, Elyse , Ahmady, Farah , Chew, Guatsiew , Charchar, Fadi
- Date: 2016
- Type: Text , Journal article , Review
- Relation: Heart Lung and Circulation Vol. 25, no. 8 (Aug 2016), p. 791-801
- Relation: http://purl.org/au-research/grants/nhmrc/1009490
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- Description: Coronary artery disease (CAD) is one of the leading causes of morbidity and mortality globally. In the last few years our understanding of the genetic and molecular mechanisms that promote CAD in individuals has increased with the advent of the genome era. This complex inflammatory disease has well-defined environmental risk factors. However, in the last 10 years, studies including genome-wide association studies (GWAS) have clearly demonstrated a genetic influence on CAD. Recently, studies on the human Y chromosome have also demonstrated that genetic variation within the male-specific region of the Y chromosome (MSY) could play a part in determining cardiovascular risk in men, confirming the notion that the increased risk for CAD in men cannot be fully explained through common CAD risk factors. Here, we review the literature about the pathophysiology of CAD, its potential causes and environmental risk factors known so far. Furthermore, we review the genetics of CAD, especially the latest discoveries regarding the implication of the Y chromosome, the most underexplored portion of the human genome to date, highlighting methods and difficulties arising in this research field, and discussing the importance of considering the Y chromosome in CAD research.
DNA copy number variations – Do these big mutations have a big effect on cardiovascular risk?
- Authors: Prestes, Priscilla , Maier, Michelle , Charchar, Fadi
- Date: 2019
- Type: Text , Journal article , Editorial
- Relation: International Journal of Cardiology Vol. 298, no. (2019), p. 116-117
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- Description: In simple terms, copy number variations or CNVs are replications or deletions in the DNA which, in humans, changes it from the normal number of two gene copies. These CNVs are caused by inherited or de novo structural changes such as duplications, insertions or deletions of repeated portions of genetic material (Fig. 1). These duplications can vary from one to ten or more copies and range in size from 50 DNA base pairs to several million [1]. Since their discovery in 1987 by Nakamura et al. [2], when they were initially named variable number tandem repeats, many studies have investigated their association with rare and common human diseases. Throughout evolution, some of these changes in copy number were beneficial such as the globin gene number duplication, while others such as the CNVs that cause Huntington's disease were not. In 2004, two landmark studies by Iafrate et al. [3] and Sebat et al. [4] found that large-scale copy-number variations, ranging in size from 100 kb to 2 Mb are common throughout the human genome, and that a high proportion of them are in known genes. These findings roused several association studies between CNVs and disease
Abnormal microRNA expression in cardiac hypertrophy and the regulation of the Endog gene
- Authors: Quarrell, Sean , Marques, Francine , Jayaswal, Vivek , Curl, Claire , Nankervis, Scott , Yang, Jean , Delbridge, Lea , Harrap, Stephen , Charchar, Fadi
- Date: 2012
- Type: Text , Journal article
- Relation: Heart, Lung and Circulation Vol. 21, no. Supplement 1 (2012), p. s7
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- Description: A deficiency in the gene for endonuclease G (Endog) was recently described as a genetic determinant of cardiac hypertrophy. The mechanisms involved in the regulation of Endog, however, are still to be elucidated. Therefore we hypothesised that Endog, being regulated by small regulatory non-coding RNAs called microRNAs (miRNAs), could contribute to the cardiac hypertrophy of the Hypertrophic Heart Rat (HHR), a human polygenic model of cardiac hypertrophy. From birth the HHR has less and smaller cardiomyocytes, which leads to hypertrophy and cardiac failure later in life. In this study, we examined genome-wide miRNA expression by Agilent Rat miRNA Microarray Kit Release 16.0 and Endog mRNA levels by real-time PCR in the left ventricle of neonatal HHR compared to age-matched rats from its authentic control, the Normal Heart Rat (NHR). Endog mRNA was significantly under-expressed in the HHR (fold change=−4.7; P=0.0001). Sixty-seven miRNAs (FDR P<0.05 and fold change>1.1) were differentially expressed between HHR and NHR (n=16). We then performed an in silico analysis to predict the miRNAs that are able to bind to the 3′ untranslated region of Endog mRNA, and therefore could regulate Endog levels. We discovered that the miRNAs let-7b, miR-338 and miR-347 are predicted to bind to Endog mRNA. Functional studies are being undertaken to determine whether these miRNAs can regulate Endog mRNA levels in vitro and their role in the pathological processes leading to cardiac hypertrophy. These miRNAs could be a new target for the prevention and treatment of cardiac hypertrophy in humans
2020 International Society of Hypertension global hypertension practice guidelines
- Authors: Unger, Thomas , Borghi, Claudio , Charchar, Fadi , Khan, Nadia , Poulter, Neil , Prabhakaran, Dorairaj , Ramirez, Agustin , Schlaich, Markus , Stergiou, George , Wainford, Richard , Williams, Bryan , Schutte, Aletta
- Date: 2020
- Type: Text , Journal article
- Relation: Hypertension Vol. 75, no. 6 (2020), p. 1334-1357
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